O2 sensor for a '98 SL1 DOHC

:banghead: i recently had my service engine light come on. when i hooked up the ob2 scanner it came up with the o2 sensor and it was bank 1 sensor 1. which sensor is that? i know there are 2 on the car one right on top and one just before the catalitic converter. which is which. can someone help me please.!!!

bank 1 is the first, one on the manifold

bank 1 is the first, one on the manifold
thanks for the help. now hopefully the damn check engine light will go out so that i may get it inspected